Not sure why the huge font, but it might be useful to specify which B&W speakers you’re speaking of.

And you you may want to be aware that this being a Sonos support forum, and not a general stereo forum, you’re likely to get info heavily weighted towards the Sonos option, whether it is correct or not.

The only way to be sure of getting a good result is to try both at home. Speaker sound quality for both will be more of a preference for one than poor quality in the other, and that can be very personal, hence this statement.
If you are already sure you like the B&W speaker sound signature, that is the way to go even without a test if the test is not possible.
PS: Ideally, the Sonos Sub is needed for all play units to deliver the best. Even a 1 pair+ Sub may meet expectations comfortably, although at a loss of line in jacks that are needed for more versatility.